making slabs

ok i know there are some threads mentioning this but i had to ask again. How do you make a cement slab, and how do you get them to look real, paint?
ive seen some with bumps like rocks and others that move and roll just like a real moutain top how is this done?


arno

Hi Arno

I suspect it's a case of you have the artistic ability or you don't........or you just keep trying till you get the results.

There are a few threads here about slabs, even some innovative constructs with lighter materials.

Cheers
Gerhard

Im pretty sure I have the artistic ability I just need the materials

Arno

These ought to help.

http://www.gardenbanter.co.uk/bonsai/52873-re-ibc-ciment-fondu-2.html

http://www.the-artistic-garden.com/hypertufa.html

http://whatcom.wsu.edu/ag/homehort/hypertufa.htm

https://www.youtube.com/watch?v=RcRJ2XbPA3I

Arno wrote:Im pretty sure I have the artistic ability I just need the materials

Arno

I don't

Arno wrote:ok i know there are some threads mentioning this but i had to ask again. How do you make a cement slab, and how do you get them to look real, paint?
ive seen some with bumps like rocks and others that move and roll just like a real moutain top how is this done?


arno

Sent you PM. hope it helps.

regards,
jun

Another recipe from a workshop I took at the North Carolina Arboretum:

1 part Portland Cement -- (this is not SACK-Crete or Quik-Crete. It is just the cement part!)
1 1/2 parts peat moss (according to the teacher Fafard brand is best)
1 1/2 ,parts Perlite or sand (sand makes the resulting slab weigh more)
A handful of "fiber mesh" (available from concrete or masonry supply stores) helps bind the materials together.

Other equipment:

Good rubber gloves
Dust mask
Some kind of mold to shape the slab or container
Cheap, seamless plastic garbage bags (or large sheets of thin plastic)
Trowel to mix ingredients
Container (large) in which to mix the ingredients
Water
A sifter or sieve helps sift out larger chunks of peat moss

.
1. Prepare the mold - use the garbage bag/plastic to line the mold. (This is used to more easily lift the molded slab out of the mold itself. Some people spray the plastic with PAM cooking spray to make removal even easier.)

2. Mix dry ingredients

3. Start adding water to the mix. Mix slowly, adding water as needed. It is ready when a handful makes a cohesive ball and when some water oozes out of the ball when you squeeze it.

4. Start filling the mold with handfuls of the mix. Press firmly into the corners and edges. If making a pot, create the bottom first, then work up to the sides. Two inches thick is perhaps the minimum thickness for a slab. More may be better. Now is the time to make drainage holes or holes for wire. Dowels of various sizes can be pushed through and left in place for the initial drying If you spray them with Pam it may be easier to remove them later.

5. Wrap the plastic loosely over the top of the slab or pot. Store indoors for 2-3 days.

6. Remove the wrapped plastic, peeling it off the molded slab. Remove the dowels if you made drainage holes; they may stick; twist them. You may have to push through a thin layer of the hypertufa at the bottom. A wire brush can be used to smooth out any rough spots.

7. Cure outside for 2-4 weeks. If you are concerned over the lime in the cement affecting the growth of the trees planned for the slab, a few months of outside exposure might be better. Personally, I don't think that is a major concern.

If any of the fiber mesh fibers are jutting out of the container, they can be burned away with a candle flame.

Remember, if your are making a large slab, the perlite will weigh much less than the sand.

Here is one method for creating slabs.

Thank you all

Jim thanks for the recipe and the links are helpful

Jun You are awesome

Jgeanagel very nice video very helpful and informitive

Ok now I got the info, time to play guess im going to home depot tomorrow

arno

Take it easy at first, don't create too long or wide slab, and practice to create different thickness. the thinner and lighter it is the better , So the structural integrity of the ribs and mesh is important. Press them hard to avoid hollow cores/honeycombs.

regards,
jun